So many repeated requests and not even the courtesy of an explanation. EN is either grossly understaffed or arrogant. Either way, it reflects badly on CEO and Board. Good feelings about the product and trust in the company are fading.

Thank you, csihilling. I'm grateful for the detail and I have been doing something similar. I will look at the website you link to. I agree, EN may not be the right tool. Problem is, I'm in it pretty deep and all real project management tools are designed for businesses - that's where the money is - and not for small groups or projects. So those tools' overhead is even worse than EN's. Really, all we want is a simple, cross-platform, collapse/expand, drag/drop outliner that can have permanent links to notes.
I am very grateful for your input. I'll report back if I find anything interesting.

Thank you.
Sorry about "work breakdown structure." It's just Project Management Institute jargon for what you're probably already doing. Iterate higher level tasks down to granular components. The sequence of top level tasks in a project are the major steps. Often we work backwards from the deliverable to the requirements. Because there's continual feedback, tasks and sequence can change frequently, especially if there are just 1-3 people on a project.
So, I appreciate your approach but the overhead is too high for what I'm trying to do. I'll keep looking and report back if I find something that works. One of the great things about EN is that it doesn't impose a way of doing things. That's why I'm trying to stay away from the project management tools that "integrate" with EN. You have to do things their way.

DTLow & csihilling. Thank you for your guidance and suggestions. An update.
Swipes reached out to me on Twitter (@PaulHindes) and said, "The integration to Evernote is activated on mobile and you can see and manage the tasks via the web & Mac app." I got through the mobile integration. It is cool that they extract just checkboxes from notes tagged "swipes", but the subtask items lose their indentation. So, there's no way to collapse/expand. There's also no way to reorder.
I also tried the widget approach mentioned in my original message. It does make it easier to get to a page of structured checkbox items. But it still doesn't solve the problem of having an actual work breakdown structure, with collapse/expand, drag and drop reordering, etc.
I have 691 tasks, total, across all my non-archived projects. They are in a work breakdown structure, imported from a now-deceased app. Of course, some are Someday/Maybe and, of the others, not all are being worked on at the same time. If I put each task of just my current projects into a separate note:
How do I maintain the initial work breakdown structure?
How do I reorder items?
Is there a way to collapse/expand to keep things intellectually manageable while still being able to see the big picture?
Thank you very much.

Thank you for responding. Agree about HTML. If necessary, a portable Java-based add-on might work. I don't have time to pursue it, unfortunately. I also agree that attachments work easily, generally. For projects that require Mendeley, for example, tighter integration would make it so much easier, but that's not essential for me at the moment.
But, back to my main problem: I'm working on multiple projects. How do you handle your projects' next actions?

This is essential to making EN the only productivity tool you need. A simple outliner to be used within notes, with optional checkboxes, collapsible levels, and drag-and-drop would do it. Without this feature, how can we actively manage? By having such a feature in EN, you might not need anything else. For fields that require (well-designed), special-purpose applications, such as academic research with apps like Mendeley, integration with EN could be readily effected via RESTful APIs.
So, I've spent several weeks looking for other apps that do this simple outlining and that integrate with EN. They all either make their product primary, so you have to do everything through their app, or they put silly restrictions on how you organize your EN notes. For example, one requires that every todo checkbox item be in a separate note. That makes it impossible to realistically do a work breakdown structure that includes subtasks. The one app that looks the most promising is Swipes, but it's not ready and it's been in development forever. It's approach is to find notes with checkboxes and just extract those. Then it will, they say, keep just checkbox items in sync without touching the rest of the note the checkbox is in. That would be brilliant.
But this is ridiculous. Without being able to use EN for active task management, it is just a repository for reference materials. But even that won't be easy to maintain if I have to keep manually linking reference notes with an outside todo manager.
There is a new kid on the block - Notebook (Mac, iOS, & Android so far) - which explicitly intends to be a replacement for EN, and it has actual todo functionality. Sync isn't finished between all platforms, but it's in active development. Also, you can sign up for the beta tests of their migration tool.
Apparently there is a mechanism to use an EN widget on Android for your EN todo items, which I'm going to try next. But it, too, puts requirements on how you organize your todos - they all have to be in the same notebook. Since I use tags instead of notebooks for my GTD organization, maybe I can make this work. Here's the description: http://www.girlxoxo.com/organizing-a-to-do-list-with-evernote-app-and-widget-digital-lifehack/
Evernote: Please. How hard would it be to create a simple outliner? It could even be a Java add-on. Maybe use something open source. I have almost finished reorganizing everything in and around EN, but that won't be sustainable without actual todo functionality. Thanks for reading.

Totally agree - there needs to be a way to close that notes list. I've been trying for a few days to take notes in EN while viewing a daily, live, time-critical video stream on my 15" MBP. Too frustrating.